We consider cooperative spectrum sensing in which multiple cognitive radios collaboratively detect the holes through energy detection and investigate optimality of with an aim to optimize performance efficient implementable way. derive optimal voting rule for any detector applied sensing. also threshold when is employed. Finally, we propose a fast algorithm large network requires fewer than total number while satisfying given error bound.

We analyze the error performance of a wireless communication system employing transmit-receive diversity in Rayleigh fading. By focusing on complex Gaussian statistics independent and identically distributed entries channel matrix, we derive formula for characteristic function (c.f.) maximum output signal-to-noise ratio. use this c.f. to obtain closed-form expression symbol probability (SEP) coherent binary keying. The method is easily extended SEP reception M-ary modulation schemes.

Cognitive radio is being recognized as an intelligent technology due to its ability rapidly and autonomously adapt operating parameters changing environments conditions. In order reliably swiftly detect spectrum holes in cognitive radios, sensing must be used. this paper, we consider cooperative optimize the performance. We focus on energy detection for find that optimal fusion rule half-voting rule. Next, threshold of determined numerically. Finally, propose a fast algorithm large network...

We present closed-form lower bounds for the performance of multihop transmissions with nonregenerative relays over not necessarily identically distributed Nakagami-m fading channels. The end-to-end signal-to-noise ratio is formulated and upper bounded by using an inequality between harmonic geometric means positive random variables (RVs). Novel expressions are derived moment generating function, probability density cumulative distribution function product rational powers statistically...

Atmospheric turbulence induced fading is one of the main impairments affecting free-space optics (FSO) communications. In recent years, Gamma-Gamma has become dominant model for FSO links because its excellent agreement with measurement data a wide range conditions. However, in contrast to RF communications, analysis techniques are not well developed and prior work mostly resorted simulations numerical integration performance evaluation fading. this paper, we express pairwise error...

In this paper, expressions for multivariate Rayleigh and exponential probability density functions (PDFs) generated from correlated Gaussian random variables are presented. We first obtain a general integral form of the PDFs, then study case when complex generating vector is circular. consider two specific circular cases: exchangeable variates evenly correlated, exponentially case. Expressions PDF in these cases obtained as well series products univariate PDFs. also derive expression...

Performance of cooperative spectrum sensing with multiple antennas at each cognitive radio (CR) is discussed in this paper. The CRs utilize selection combining the decision statistics obtained by an improved energy detector for making a binary presence or absence primary user (PU). uses arbitrary positive power p amplitudes samples PU's signals. CR orthogonally forwarded over imperfect reporting channels to fusion center, which takes final hole. We derive expressions probabilities false...

This paper considers transmit antenna selection (TAS) and receive generalized combining (GSC) for secure communication in the multiple-input-multiple-output wiretap channel, where confidential messages transmitted from an NA-antenna transmitter to NB-antenna legitimate receiver are overheard by NE-antenna eavesdropper. We assume that main channel eavesdropper's undergo Nakagami-m fading with parameters mB mE, respectively. In order assess secrecy performance, we present a new unifying...

There is an increase in usage of smaller cells or femtocells to improve performance and coverage next-generation heterogeneous wireless networks (HetNets). However, the interference caused by neighboring a limiting factor dense HetNets. This being managed via distributed resource allocation methods. as density network increases so does complexity such Yet, unplanned deployment requires adaptable self-organizing algorithm make HetNets viable. As such, we propose use machine learning approach...

This paper develops a tractable framework for exploiting the potential benefits of physical layer security in three-tier wireless sensor networks (WSNs) using stochastic geometry. In such networks, sensing data from remote sensors are collected by sinks with help access points, and external eavesdroppers intercept transmissions. We focus on secure transmission two scenarios: 1) active transmit their to points 2) forward sinks. derive new compact expressions average secrecy rate these...

In this letter, we propose joint relay selection and power allocation schemes for maximization of the throughput an amplify-and-forward (AF) cooperative communication system where source relays are energy harvesting (EH) nodes. We formulate offline optimization problem which can be solved optimally by generalized Bender's decomposition. For real-time implementation with low computational complexity, two suboptimal online schemes. The performance proposed is evaluated via simulations.

We derive closed-form expressions for the single-user capacity of maximal ratio combining diversity systems taking into account effect correlation between different branches. consider a Rayleigh fading channel with two kinds correlation: 1) equal branch signal-to-noise ratios (SNRs) and same any pair branches 2) unequal SNRs arbitrary such that eigenvalues covariance matrix are all distinct. Three adaptive transmission schemes analyzed: optimal simultaneous power rate adaptation; adaptation...

We present an analysis of a hybrid selection/maximal-ratio combining diversity system over evenly correlated slow frequency-nonselective Nakagami fading channel, where the correlation coefficient between any pair branch gain amplitudes is same, and all average signal-to-noise ratios (SNRs) are equal. In this system, L branches with largest instantaneous SNR out N available selected combined using maximal-ratio combining. From joint characteristic function (cf) SNRs, we obtain expression for...

In this paper, we investigate modulation techniques for end-to-end communication between two nanomachines placed in a fluid medium. The information is encoded as the number of molecules transmitted leading to such schemes being aptly named amplitude schemes. propagation obeys laws Brownian motion with positive drift from transmitter receiver nanomachine. channel characterized by parameters medium: velocity and diffusion coefficient. Assuming degrade over time, life expectancy also plays...

In this paper, we consider optimal power allocation for conventional and buffer-aided link adaptive energy harvesting (EH) relay systems, where an EH source communicates with the destination via decode-and-forward {over fading channels}. relaying, transmit signals in consecutive time slots whereas state of source-relay relay-destination channels {as well as amounts available at relay} determine whether or is selected transmission. Our objective to maximize system throughput over a finite...

Multihop communication is considered to be a useful approach for improving the coverage area with reduced transmit power. In this paper, we consider path-selection-based multihop decode-and-forward (DF) cooperative system. A simple parallel path-based system considered. It assumed that all hops in paths are subject independent Rayleigh fading. The best path, is, link between source and destination, selected based on max-min selection criterion. relays path use symbol-wise DF protocol, which...

Cooperative spectrum sensing in a multihop cognitive radio (CR) network based on multiple antennas using an improved energy detector is studied this paper. The uses the pth power of absolute value samples primary user's (PU's) signals. We replace conventional by to enhance performance CR. Analytical expressions probability false alarm and missed detection each CR are derived. Furthermore, we extend our study cooperative diversity system containing secondary transmission paths between PU...

The use of repeaters (relays) has recently been introduced in power line communication (PLC) systems for long-distance data transfer and thus, it becomes important to analyze the performance relay based PLC systems. A simplified system model with distance dependent signal attenuation additive white Gaussian noise may not cover all factors affecting transfer, such as variation amplitude (fading) occurrence impulsive noise. Hence, a more realistic log-normal fading, attenuation,...

In this paper, we propose a new relaying scheme, referred to as priority-based max-link relay selection, for buffer-aided decode-and-forward cooperative networks. We give the first priority buffers having status full, second empty, and third neither full nor empty. The best node is selected corresponding link highest channel gain among links within class. By adopting Markov chain approach analyze state transition matrix that models evolution of status, derive analytical expressions outage...

This paper considers orthogonal space-time block coded transmission for a multiple-input multiple-output channel (MIMO) with non-coherent amplify-and-forward (AF) relaying in Rayleigh fading. We first characterize the statistical properties of instantaneous signal-to-noise ratio (SNR) at destination, by deriving new exact closed form expressions moment generating function, cumulants, and second moments. These results show reciprocity relationship between number antennas relay destination....

In this paper, performance of cooperative spectrum sensing with an improved energy detector is discussed. The Cognitive radios (CRs) utilize for taking a decision the presence primary user (PU). uses arbitrary positive power p amplitude received samples user's signals. each CR orthogonally forwarded to fusion center (FC), which takes final PU. We minimize sum probability false alarm and missed detection in obtain optimized number CRs detecting hole. An value threshold also obtained by...

In this letter, a cognitive radio-based simultaneous wireless information and power transfer system consisting of one base station, desired receiver, multiple primary users, energy harvesting receivers is considered. Each link in the suffers from small scale fading path loss. We focus on secrecy outage network, keeping mind that may act as potential eavesdroppers. A closed-form analytical expression for exact probability derived, some useful insights are obtained. Numerical Monte Carlo...

The authors present a study on the end‐to‐end average bit error rate (BER), channel capacity and outage performance of multi‐hop power line communication (PLC) system equipped with decode‐and‐forward (DF) relays. To combat issue distance dependent signal attenuation, data transmission has recently been introduced for PLC systems. However, apart from systems also suffer (i) variation in amplitude (fading) because reflections (ii) impulsive noise. Thus, this study, each hop is modelled by...

In this letter, a system model for beyond 5G communication networks utilizing the potential of both index modulation and reconfigurable intelligent surface (RIS) based schemes is investigated. An analytical framework performance evaluation considered which does not involve complicated phase distributions developed. The RIS-space-shift keying (RIS-SSK) RIS-spatial (RIS-SM) using greedy detector analyzed, novel closed-form expressions probability erroneous receive antenna detection are...